Grease gun



2 Sheets-Sheet ATTRNEYJ May 3, 1932. c. R. BucHl-:T

GREASE GUN Filed May 5l, 1928 4 BY Wwf/ZM 7M May 3, 1932 l c. R. BUCHE-r 1,856,372

GREASE GUN Filed May 51, 1928 2 sheets-sheet 2 u a 33 il if J9 Y 1e I g:

7 2 1 w 1 d 1 M ,nlll i 'mu I INVENTOR.

A TTORNEY5 Patented May 3, 1932 UNITED STATES PATENT OFFICE CONRAD ROBERT BUCKET, OFIJONG BEACH, CALIFORNIA, ASSIGNOR, BY MESNE AS- SIGNMENTS, T0 ALEMITE CORPORATION, 0F CHICAGO, ILLINOIS, A CORPORATION 0F DELAWARE GREASE GUN Application filed May 31, 1928. Serial No. 281,925.

This invention relates to a grease gun of a character suitable to inject lubricating grease under pressure into cavities, chambers, bearings and like places. It .appertains more particularly to a gun wherein the pressure under which the lubricant is ejected 1s obtained by the action of a Huid actuated motor. The present invention is adapted to be connected to a source of supply, suchas a compression tank and to boost the ejection pressure of the grease, or to have attached thereto a grease supply receptacle fornnng with the gun a unit. 0

The objects of this invention are to provlde a grease gun of the character described havan or all of the following features.: a va ve or the control of actuating fluid which normally places the motor member in communication with the exhaust and is operable to connect the motor to a source of supply of actuating iiuid under pressure; a reciprocable plunger valve and operating trigger therefor; a casing having a grease ejector barrel, a motor, and means for interchangeably connecting the casing to various types of grease supply chambers; a grease supply chamber detachably mounted on the casin l and supplying grease to the ejector barre under pressure; a grease supply chamber having a iioating displacement piston operable to force'grease therefrom and actuated indirectly by thefluid actuating the motor; a casing having anejector barrel, a motor cylinder and a handle for manipulation thereof, which handle is associated with a valve operating trigger; and a grease gun of the character described having the grease moved by 1niiuence of three stages of pressure obtained by an actuating fluid.

These objects are obtained by means of the embodiment of my invention illustrated 1n the accompanying drawings in which Fig. 1 is an elevation partly in section of a grease gun having a supply chamber member partly attached thereto adapted to be connected to a compression tank as shown 1n Fig. 5; Fig. 2 is a section through the grease having a supply chamber member attached thereto and forming a complete unit; Fig. 3 is a section as seen on the line 3 3 of Fig. 2 on an enlarged scale; Fig. 4 is a bottom view as seen on the line 4 4 of Fig. 2; and Fig. 5 is a view showing the unit associated with a compression tank.

Referring more particularly to the drawings,the grease gun comprises a casing having an ejector barrel 6', the bore of the barrel ending in a nozzle 7 adapted to have a hose or any approved type of coupling attached thereto. The casing has a motor cylinder 8 formed thereon in alinement with the ejector barrel and having a bore of much greater diameter than the bore of the ejector barrel. The barrel portion has an extension 9 through which the bore of the ejector barrel extends. Threaded onto the end of the casing so as to close the cylinder barrel is a head 10 having a laterally projecting handle 11 provided with finger grips. On one side of the casing is an annular extension 12 internally threaded to serve for attachment of a supply chamber. Hinged to the handle so as to overlie the latter is a trigger 13.4

Slidably mounted in the bore of the plunger barrel is a plunger 14: having at its outer end a piston 15. Bearing against the rear of the piston 15 is a compresslon spring 16 urging the piston and plunger into their initial ejecting positions. Extending through the casing and communicating with the bore of the ejector barrel is a passage 17 serving for the supply of grease from the supply chamber to the ejector and providing a port which is traversed-by the plunger 14 on its displacement stroke. In the casing and communicating with the motor cylinder to the rear of piston 15 is a relief passage 18 controlled by a check valve 19 so s to permit the entrance of air and prevent discharge therefrom. A passage 20 also communicates with the motor cylinder and opens through a boss 21 internally threaded and disposed within the annular extension. A check valve 22 prevents inflow of air into the piston cylinder.

The handle 11 has a main passage 23 communicating with the motor cylinder 0n the front side of piston 15. This main passage connects with a valve chamber 24 extending transversely through the handle and enlarged at the inner end. The enlarged portion is internally threaded to receive a closure plug 25. Extending through the handle is an mlet passage 26 communicating with the valve .chamber and internallyl threaded. to adapt 1t for connection to an air hose or hke 'supply line for Huid under pressure. A

plunger valve 27 is mounted in the valve chamber, it having peripherally located passages so that air may travel longitudinally of close the port4 opening to the atmosphere,

when the head is seated against the handle.

4On the other end of the plunger is an enlargement 29 havinga seat to co-operate with a corresponding seat to Acontrol the flow of air between the inlet passage 26 and the main ypassage 23. A socket is formed in the opposing ends of the valve plunger and the closure plug 25,Y and mounted therein is a compression spring 30 tending to hold the plunger valve in its outer position with communication between inlet`ports 26 and `the main passage 23 closed. The head of the plunger underlies the trigger 13.

Referring more particularly to Fig. 1, a supply chamber member 31 is shown attached to the extension. This memberhas a vcoupling extension 32 adapted to be connected to a supply hose. For convenience in operation, there isan 'extension 33 internally threaded to receive the stem 34 of a screw valve 35 adapted to be seated and to close inlet 17. A handle 36 serves for convenient operation of this valve.` l

Referring more particularly to Fig. 5, the gun is shown connected to a compression tank 37. This tank is adapted to hold grease of the character which is introduced into automobile diferential casings and transmission cases. The inlet passage in the handle is connected by an air hose 38 to a threeway valve 39, one branch of which is connected to the tank 37 to supply pressure `thereto, and the other branch of which is connected by a hose 40 leading to a source of air under pressure. The coupling 32 is connected by a hose 41 to the discharge of a fluid meter 42 which measures the grease discharged from the tank 37. A pressure gage 43 is shown on the tank.

During inoperation of the system shown in Fig. 5, valve 35 is maintained closed vso that grease will not pass from the tank to the Vejector barrel and be wasted therefrom.

When it is desired to dispense grease, the valve 35 is opened by turning the handle 36. The valve 39 on the tank is then opened, and air supplied through the hose 40. In the event that the pressure is sufficient, grease will then flow through the discharge nozzle. However, if the back pressure against which the grease is to be discharged is greater than ,closed thereby.

that which would create a How, the tri ger 13 is depressed to move the plunger va ve inwardly and close the main passage 23 to the atmosphere. Movement of the plunger valve to a position closing communication with the atmosphere, opens communication between the inlet passage 26 and the main passage, and air is supplied to the motor cylinder in front of piston 1'5, causing the piston to be moved against the action of spring 16 and forcing the plunger 14 into the ejector barrel so that it overrides the grease inlet port 17 and closes the latter. In its continued travel, the lpressure upon the grease in the ejector barrel isA boosted. lDuring the working stroke of piston 15, the check valve 19 closes the relief port and air will pass through the port 20 to the supply chamber. When the piston has reached the end of its working stroke, the trigger 13 is released, and spring 30 causes the plunger Valve to be moved connecting the motor cylinder with the atmos` phere and shutting off connection with the inlet passage 26. The spring 16 will then return the piston and plunger to their initial positions for another cycle of operation.

pon the return of the piston 15, the relief head 45 secured to the cylinder by threads.

At the center of the head is an opening 46 which extends through a boss 47 Slidably mounted in the opening 46 is a tubular rod 48, the upper end of which is threaded into the boss 21. At the lower end of the rod are openings 49, and secured to the rod on the outer side of the head is a collar 50 which is adapted to it snugly against the boss 47 and form a seal therewith. A handle 51 is secured to the end of the rod, the latter being On the upper end of the rod are lugs 52. Slidably mounted in the rod is a iioating piston 53.

The structure just described is used in the following manner: the handle 11 is connected to an air hose. The handle 51 is turned to detach the rod 48 from the boss. The cylinder 44 is detached, and the open end plunged into a supply of grease. The handle 51 is then pulled outwardly to draw a charge of grease into the supply chamber, the piston being moved toward the head 45. The cylinder 44 with its charge is again attached to the casing, the rod 48 pushed inwardly and attached to the boss 21. v

T he handle 51 is screwed up tight, so that the collar 50 seals the space at the rod, and the gun is now ready for introduction of grease to the ejector barrel. Trigger 13 is depressed to admit air in front of the piston 15,

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Leaders the latter being advanced and forcing air in back of it through the passage 20, rod 4:8 and openings 49 below' the piston 53 which is urged upwardly and forces grease toward the port 17. Check valve 22 prevents the air injected into the cylinder 44 below the piston from returning, upon release of the trigger 18. Upon another operation by depression ofthe trigger i3, the grease which has entered the ejector barrel will be forced outwardly through the nozzle.

YWhat l claim is:--'

l. A grease gun having a casing comprising a grease barrel and a motor cylinder, an ejection nozzle for said barrel, an inlet for supply of grease to said barrel, an extension on said casing in communication with said inlet, a plunger in said barrel; a motor cylinder, a piston therein for actuating said plunger, a main passage for actuating fluid communicating with said cylinder, an eX- haust passage and 'an inlet passage connected to said main passage at a common juncture formed with a valve chamber; a valve in said valve chamber movable to place said main passage either in communication with said inlet passage or said exhaust passage, means to operate said valve; a supply chamber detachably connected to said extension, a (iev tachable head on said chamber, a tubular rod slidably mounted in said head and detachably connected to said casing, a passage in said casing placing the motor cylinder in communication with said rod and in communication with the outer end of said chamber, and a floating piston on said rod for urging grease from said supply chamber through said inlet.

2. The combination in a grease gun of a cylindrical housing having an enlarged chamber therein open at one end, a closure member therefor comprising a combined handle and valve housing, a cup leather piston in said chamber, a plunger projecting therefrom and extending into a bore in said housing a grease reservoir attached to said housing, a pair of spring-pressed ball valves mountedin said housing closing air passage- Ways, one of said passageways extending to atmosphere and the other communicating with the rear end of the grease reservoir, a passageway in the housing connecting the grease reservoir and the bore in said housing, a source of air under pressure connected With said valve housing, a normally closed valve in said valve housing and means for opening said valve to allow yair to enter the housing chamber to force the plunger forward ejecting lubricant and simultaneously forcing air from the housing chamber to the rear of the lubricant reservoir.

3. The combination in a grease gun of a cylindrical housing having an enlarged chamber therein open at one end, a combined valve housing and handle unit arqqs ranged to close the end of said chamber, a reciprocable piston in said chamber, a plunger projecting therefrom and extending inte a bore in said housing, an inlet for a supply of grease to said bore, a grease reservoir at tached to said housing., a pair of one-Way valves mounted in said housing closing air passageways, an inlet passage extending to atmosphere and an outlet passage communieating with the rear end of the grease reservoir, a source of air under pressure connected to said combined handle and valve housing unit, a normally closed valve in said` unit and trigger means attached to said unit for opening said valve to allow air to enter the housing chamber to force the plunger forward to eject lubricant and simultaneous ly forceair from the housing chamber to the rear of the lubricant in the reservoir.

In Witness that I claiml the JIoregoing l have hereunto subscribed my name this 24th day of May, 1928.

CONRAD ROBERT BUCHET. 

